In the prior art, various types of brushes, brush assemblies, and brush-making apparatus and methods have been proposed. These brushes are used in a variety of applications, including street sweepers, sweeping machines for airport use, deburring machines, and the like. U.S. Pat. No. 4,998,316 to Maltarp (herein incorporated in its entirety by reference) discloses one type of a brush that is formed into a ring for use on mandrels for sweeping, brushing, etc. Referring to FIG. 1, one brush product of Maltarp is designated by the reference numeral 10 and includes wires 1 formed into a brush assembly for use with a ring. A plastic annular hub 3 is formed on one end of the wires to hold the wires in place. A metallic ring 5 is then crimped around the plastic hub, the crimped portions designated by reference numeral 7. The Maltarp patent is an improvement over wire brushes that employed locking wires within the metallic ring.
As part of the manufacturing process, the Maltarp patent takes wire brush material and cuts them to length. The brushes are laid horizontally and pass through an extruder station wherein a thermoplastic material is extruded on one end of the wires. The wire-plastic combination is shaped and cooled to form a continuous wire mat, which can be cut to length. Once cut, the wires are conveyed to a hydraulic press, wherein the mat is folded into a ring shape, and then a wire ring is fixed to the mat to form the completed brush.
While Maltarp discloses wires as the brushing materials, other brushes employ all polymer construction as is disclosed in U.S. Pat. No. 5,819,357 to Gould. This construction is an all-polymer construction wherein polymer bristles are used with a polymer strip. The strip is configured to slide into channels in a mandrel of a sweeping machine. The brush construction comprises bristles extending from a base strip. Molding the bristle ends into the base strip forms the brush construction.
FIG. 2 shows a schematic of a prior art apparatus designated by the reference numeral 150 for taking brush material in the form of filaments and forming them into a mat for use in a brush. The filaments are provided in a container 151 held on a scissors lift 153. An operator 155 supervises the feeding of the filaments 157 into a hopper 159. The filaments are directed to a conveyor 161 which allows the extrusion of the thermoplastic material on the filament ends. A cutter 163 cuts the thus-formed mats 165 for use in brush making, the mats directed by conveyor 167 to the appropriate next location for brush manufacture. Another operator 169 supervises the finishing end of mat manufacture.
When making brushes using polymer filaments, the filaments are made by an extrusion apparatus 70 as shown in FIG. 3. The polymer raw material 71 is fed to an extruder 73, which produces an extruded continuous output of filament 75. The filament passes through a stretcher oven 77 to give it is proper orientation, and then the filaments are cooled in water tank 79, and cut to length by cutter 81. An operator 83 supervises the termination of the filament production, wherein the cut to length filaments 57 are boxed and then skidded at 79.
U.S. Pat. No. 6,665,902 to Vegter, herein incorporated by reference in its entirety shows other examples of brush constructions. In this patent, a hub is formed on the ends of metallic wires and the hub is attached to a base. The base is configured with members for holding the assembled brush assembly in a brushing apparatus.
While there are numerous ways to form brush assemblies, these methods have there shortcomings in terms of productivity and efficiency. That is, filaments used in the brush making operation are taken from stock. The stock filaments are extruded in various sizes and lengths, and the brush manufacturer purchases the desired sized filaments for the brush making operation. The brush making operation is a basically a batch operation as shown in FIG. 2 which is designed to run based on a quantity of fed filaments, wherein the filament stock is selected for a given run of the brush making apparatus. Once the feed of filament is depleted, the apparatus is idle until the feed of filament is replenished. In addition, the feeding of the filaments into the brush making operation must be monitored by personnel to ensure that the feed hopper containing the filaments to be discharged onto the conveyor is full.
Therefore, a need exists to provide improvements in the field of brush manufacture. The present invention responds to this need by integrating the continuity of a filament making operation with the brush making operation that normally relies on the use of stocked supplies of filament.
While the brush making operation and filament extrusion operations are employed separately in the field of brush making, no one has combined the two given the inherent conflict between an operation that continuously produces a filament and an operation that is designed to run on a controllable source of raw material, i.e., stock filaments.